1. Field of the Invention
The present invention relates to a method of producing non-oriented electrical steel sheet having high magnetic flux density and low core loss.
2. Description of the Prior Art
In recent years, the need to save energy has led to an increasing demand for higher quality non-oriented electrical steel sheet for use as the core material of small rotating machines. In response, manufacturers of electrical steel sheet have been conducting research and development into ways of improving the magnetic properties of non-oriented electrical steel sheet and have produced a number of low-grade non-oriented electrical steel sheets based on JIS specifications.
Conventionally various technical means have been employed to produce such low-grade non-oriented electrical steel sheets having low core loss values, including raising the purity of the steel during the melt step, increasing the silicon content, and using a sufficient temperature and time period during finish annealing.
However, a problem has been that while these techniques reduced the core loss values of the steel, at the same time the magnetic flux density also was reduced, limiting the degree of energy-saving that was possible.